This invention relates to a railroad turnout and specifically to an improved railroad turnout utilizing concrete railroad ties.
Typically, a turnout 10 (FIG. 1) is a device used in railroading to direct a train moving on an entry track 12 to one of multiple discharge tracks 14. The entry track 12 includes two spaced apart rails 16, which are continuous with outer rails of the discharge tracks. The inner rails 18 of the discharge tracks 14 intersect and are joined by a device known as a frog 20. As in a typical railroad track, railroad ties 22 used in a turnout are spaced at predetermined intervals below the rails 16. Historically, hardwood railroad ties have been used, but concrete railroad ties have been used in modern railroads for many years. Concrete railroad ties are very heavy, weighing as much as three times that of a hardwood railroad tie.
The turnout comprises a switch section, a closure section, a frog guardrail section and a heel section. In each of the sections, the rails are mounted on varying lengths of railroad ties. The length of the railroad tie varies with respect to its position in each section. Typically, it is desirable to maintain a constant length overhang of railroad tie between the outer rails and the end of the railroad tie. In the utilization of concrete railroad ties, it is sometimes necessary to have a separate railroad tie pattern for each railroad tie needed. This is both time consuming and costly. A conventional concrete railroad tie turnout assembly 24 is shown in FIG. 2a. At each rail seat area 26 where a rail 28 is to be fastened to a concrete railroad tie 30, either cast in shoulder inserts 31, 32 are provided opposing each other on field and gauge sides of the rail seat area 26, respectively or bolted steel plates 34 with attached fastenings. The cast in shoulder inserts 31, 32 (FIGS. 2b, 3a and 4) are permanently mounted within the concrete railroad tie 30 at a position directly adjacent to the rail 28. An insulator spacer 36 is placed adjacent to and abutting the base or toe 38 of the rail 28 between the rail 28 and the shoulder insert 31, 32 with an elastomeric pad 40 beneath the rail 28. A retaining clip 42 is attached to a shoulder insert 31, 32 by way of inserting through a longitudinal receiving hole 44 in a shoulder insert 31, 32, pressing upon the outer surface of the corresponding insulator spacer 36 to rigidly secure rail 28 to the concrete railroad tie 30. This arrangement is the most cost effective from a raw material standpoint, but requires a separate unique pattern for each concrete railroad tie. An advantage therefore exists for a turnout assembly requiring a reduced number of concrete railroad tie patterns and the fewest bolted plate rail seats.
A concrete railroad tie turnout assembly 46 (FIGS. 5-8) developed in 1989 by KOPPERS INDUSTRIES INC. (a partner in KSA, the assignee of the present invention) addressed some of the problems associated with concrete railroad tie turnouts by reducing the number of concrete railroad tie patterns needed. In this assembly, concrete railroad ties 48 were laid in groups 50 having the same lengths (FIGS. 5 and 6.) Each group includes railroad ties 48 having the same length while the next downstream group includes railroad ties 48 which are six inches longer than the preceding group. Typically, each group in the example consists of one to four railroad ties 48. The concrete railroad ties 48 utilized in these turnouts 46 have cast steel inserts in the form of bolt receptacles 50. Oversize eight-inch steel plates 52 are bolted to the bolt receptacles so that the steel plates 52 rest on top of rubber pads 54 that lie between the plates 52 and the upper surface of the concrete railroad ties 48. A railroad tie shoulder 56, 57 is welded to each steel plate 52 at a predetermined location on the steel plate 52 (FIGS. 7 and 8). By utilizing this assembly (bolted-on plate turnout), the amount of concrete tie patterns needed in a standard #7 turnout is reduced from forty to sixteen. A further advantage therefore exists for a turnout assembly requiring a reduced number of concrete railroad tie patterns while also making the ties of each length interchangeable with railroad ties of the same length in any number turnout of either left or right hand. All unique fittings or fastenings are entirely on the bolted plates. This arrangement also has advantages in reducing the required number of maintenance spare railroad ties.
In accordance with one embodiment of the present invention, a turnout assembly is assembled having concrete railroad ties to which rails are attached using fasteners. The type of fasteners used depends on the position of the fastener within the turnout assembly. The fastener used is selected from a group including conventional cast shoulders, bolted steel plates and steel plates cast directly into the concrete railroad tie so that the top surface of each cast steel plate is substantially flush with the top surface of the concrete railroad tie. Fasteners for the rails are welded to predetermined positions on the steel plates. Additionally, each cast in steel plate can be cast into one or more positions on the concrete railroad tie thus, creating more flexibility as to the positions of the rail fasteners on the railroad tie and reducing the length of the cast in steel plate needed. The cast in steel plate rail seats with weld on shoulders are more costly than rail seats with cast in shoulders, but significantly less costly than bolted steel plates.
Other features of the invention will be apparent from the following description, the accompanying drawings and appended claims.